It is preferred that a semiconductor device has unique identification information (also called a fingerprint) in order to distinguish individual devices from other devices or to enable encrypted communication between devices. Until now, unique identification information was either individually assigned by a vendor or individually set by a user.
However, it was a burden on vendors and users that vendors individually providing unique identification information or users individually providing unique identification information.
Therefore, semiconductor devices have been developed mounted with a circuit for automatically generating unique identification information. For example, US2014/0325237 to Van Der Leest et al. takes advantage of the fact that data in an initial state at the time of power-on of a SRAM is different for each chip. Since data which is different for each chip does not have high reproducibility, a large-scale error correction process is performed in order to increase reproducibility. Data generated here is called Physical Unclonable Function Data (PUF DATA).
For example, SRAM requires a capacity of 8 Kbit in order to generate 256 bits as PUF DATA. A 100K cycle is required for error correction processing, and a control circuit for achieving this requires a 15K gate.